Iron replacement therapy in heart failure: a literature review

BACKGROUND: Heart failure (HF) is a major global challenge, emphasised by its designation as the leading cause of hospitalisation in those aged 65 and above. Approximately half of all patients with HF have concurrent iron deficiency (ID) regardless of anaemia status. In HF, iron deficiency is independently associated with higher rates of hospitalisation and death, lower exercise capacity, and poorer quality-of-life than in patients without iron deficiency. With such consequences, several studies have investigated whether correcting ID can improve HF outcomes. Main body. As of 1st June 2021, seven randomised controlled trials have explored the use of intravenous (IV) iron in patients with HF and ID, along with various meta-analyses including an individual patient data meta-analysis, all of which are discussed in this review. IV iron was well tolerated, with a comparable frequency of adverse events to placebo. In the context of heart failure with reduced ejection fraction (HFrEF), IV iron reduces the risk of hospitalisation for HF, and improves New York Heart Association (NYHA) functional class, quality-of-life, and exercise capacity (as measured by 6-min walk test (6MWT)) distance and peak oxygen consumption. However, the effect of IV iron on mortality is uncertain. Finally, the evidence for IV iron in patients with acute decompensated heart failure, or heart failure with preserved ejection fraction (HFpEF) is limited. CONCLUSIONS: IV iron improves some outcomes in patients with HFrEF and ID. Patients with HFrEF should be screened for ID, defined as ferritin < 100 µg/L, or ferritin 100-299 µg/L if transferrin saturation < 20%. If ID is found, IV iron should be considered, although causes of ID other than HF must not be overlooked.